Importing code and sys.path

We have a custom codebase that we were planning to run parts of through distributed.
Multiple users, each developing their own code tree - I set up an EC2Cluster, added workers, and we NFS mount everyone’s home directory to all workers to get access to the custom code.

However, in order for import to work, we normally add the repo to sys.path, then import things relative to the repo. If I modify sys.path on the workers, it seems to be global across all clients and all users.

How is that meant to work for a general-purpose multi-user cluster, if there’s no isolation, and each of them can accidentally trash each other’s configuration? Am I missing some fundamental element of setup, or way we can turn some level of protection on to at least isolate different client connections from each other?